Effluent Guidelines

Steam Electric Power Generating Effluent Guidelines

Rule Summary

EPA promulgated the Steam Electric Power Generating Effluent Guidelines and Standards (40 CFR Part 423) in 1974, and amended the regulations in 1977, 1978, 1980, 1982 and 2015. The regulations cover wastewater discharges from power plants operating as utilities. The Steam Electric regulations are incorporated into NPDES permits.

What is Steam Electric Power Generating?

Steam electric plants use nuclear or fossil fuels (such as coal, oil and natural gas) to heat water in boilers, which generates steam. The steam is used to drive turbines connected to electric generators. The plants generate wastewater in the form of chemical pollutants and thermal pollution (heated water) from their water treatment, power cycle, ash handling and air pollution control systems, as well as from coal piles, yard and floor drainage, and other miscellaneous wastes.

Related Information

Note: the NAICS group listings are provided as a guide and do not define the coverage of the Steam Electric regulations. For precise definitions of coverage, see the applicability sections in 40 CFR Part 423.

Facilities Covered

The Steam Electric Power Generating Effluent Guidelines apply to a major portion of the electric power industry. These are plants primarily engaged in the generation of electricity for distribution and sale which results primarily from a process utilizing fossil-type fuel or nuclear fuel in conjunction with a thermal cycle employing the steam water system as the thermodynamic medium. There are approximately 1,100 of these facilities located throughout the United States.

2015 Final Rule - Amendment

Background Documents

2009 Detailed Study

EPA conducted a study which provided an industry overview, data on wastewater characteristics of coal-fired plants, a description of applicable wastewater treatment technologies, a discussion of trends in the use of air pollution controls, and a description of environmental impacts.